H18 CARRY OUT A VISUAL INSPECTION ON THE INTAKE AIR SYSTEM AND ALL VACUUM HOSES
Check the intake air system for leaks, obstructions, and damage.
Inspect the entire length of all the vacuum hoses for: proper connections.
Damage or cracks.
Damaged or cracked vacuum tees.
Verify the integrity of the positive crankcase ventilation (PCV) system.
Verify the proper PCV valve part number.